Signal just released the usernames for both desktop and mobile now, with phone number hiding. This makes it easy to join groups without leaking info to the group.

Get the full guide w/ dope groups to join, including Monero focused ones from Tuxsudo of the MoneroTalk podcast: https://simplifiedprivacy.com/signal-usernames-desktop/

Tor Browser Onion: http://privacypkybrxebcjicfhgwsb3coatqechwnc5xow4udxwa6jemylmyd.onion/signal-usernames-desktop/